Short answer questions Flashcards
What are the major functions of the following 10 structures from the brain and brain stem:
- Cerebral cortex
- Corpus collosum
- Pre-central gyrus
- Post-central gyrus
- Cerebral peduncles
- Cerebral aqueduct
- Pons
- Medulla oblongata
- Pyramids
- Diencephalon
- Cerebral cortex - the largest site of neural integration consisting of grey matter
- Corpus collosum - nerve fibres that connect the right and left hemispheres and allow them to communicate
- Pre-central gyrus - the primary motor cortex
- Post-central gyrus - the primary somatosensory cortex
- Cerebral peduncles - connect the cerebrum to brainstem, carrying information
- Cerebral aqueduct - a channel that allows CSF to flow between the 3rd and 4th ventricle
- Pons - the bridge linking the cerebellum with the midbrain, diencephalon, cerebellum and spinal cord
- Medulla oblongata - connects brain to spinal cord and is responsible for complex autonomic reflexes and control of visceral functions
- Pyramids - bundles of fibres which contain the pyramidal tracts
- Diencephalon - acts as a primary relay and processing centre for sensory information and autonomic control, consists of the thalamus and hypothalamus
Write a short definition for each of the following five structures of the CNS:
- White matter
- Anterior horn of the grey matter
- Lateral corticospinal tract
- Post-central gyrus
- Fourth ventricle
White matter - neural tissue which contains a high proportion of myelinated axons
Anterior horn of the grey matter - anterior division of spinal cord grey matter, contains cell bodies of motor neurons
Lateral corticospinal tract - fibres which decussate in the medulla oblongata and send signals contralaterally to extremity muscles
Post-central gyrus - primary somatosensory centre
Fourth ventricle - cavity in the brain stem filled with CSF. Conncects to subarachnoid space and spinal canal
Describe the passage of blood through the entire heart, beginning with the inferior vena cava through to the aorta. In your answer include which circuits, vessels, chambers and valves are involved in the process
- Deoxygenated blood returning from the systemic circuit passes into the right atrium during atrial diastole via the inferior and superior vena cava, and the coronary sinus
- This blood then passes through the tricuspid valve into the right ventricle during ventricular diastole. Contraction of the right atrium forces extra blood into the right ventricle.
- During ventricular systole AV valves close and Pulmonary semilunar valve open to allow blood to flow into the pulmonary circuit. The deoxygenated blood first flows through the pulmonary trunk and pulmonary arteries to the pulmonary capillaries where the blood is oxygenated.
- Oxygenated blood returning from the pulmonary circuit passes into the left atrium during atrial diastole via the pulmonary veins
- This blood then passes through the bicuspid valve into the left ventricle during ventricular diastole. Contraction of the left atrium forces extra blood into the left ventricle.
During ventricular systole the bicuspid valves closes and the Aortic semilunar valves open to allow blood to flow into the systemic circuit. The oxygenated blood first flows through the aorta and systemic arteries to the systemic capillaries where the blood is delivered to tissues. This blood returns to the right atrium via the inferior and superior vena cave, and coronary sinus
In regards to the corticospinal tracts, please answer the following questions:
- What organs/structures do the corticospinal tracts innervate?
- What are the structural differences between the lateral and ventral corticospinal tracts?
- How do the functions of the lateral and ventral corticospinal tracts differ?
- Where are the cell bodies of the upper and lower motor neurons for the corticospinal located? Provide an answer for upper and lower motor neurons
- What is the alternate name for the corticospinal tract?
The corticospinal tracts carry signals from the primary motor cortex to innervate muscles of the trunk and limbs
The lateral corticospinal tract decussates at the pyraminds of the medulla oblongate while the ventral corticospinal tract decussates at the spinal cord
The lateral corticospinal tract sends fibres to extremity muscles for voluntary movements while the ventral corticospinal tract sends fibres mainly to the trunk and axial muscles
Upper motor neuron cell bodies located in primary motor cortex. Lower motor neuron cell bodies located in ventral horn of spinal cord
Pyramidal pathways
In regards to the sympathetic nervous system, write short definitions for each of the following:
- Postganglionic fibre
- Sympathetic chain
- Collateral ganglion
- Adrenal medulla
- Hypothalamus
Postganglionic fibre - nerve fibres that run from the ganglion to the effector organ
Sympathetic chain - a paired bundle of ganglionic nerve fibres that runs from the base of the skull to the coccyx
Collateral ganglion - sympathetic ganglia which lie between the sympathetic chain and the organ of supply
Adrenal medulla - the inner part of the adrenal gland which controls hormones that initiate the flight or fight response
Hypothalamus - a portion of the brain which is the main visceral control centre of the body
List 3 key accessory organs of the digestive system. Give a key function that contributes to the digestive process for each, and describe where they are connected to the GI tract
Liver
- Sits directly inferior to the diaphragm in the right hypochondriac region
- Key function is to filter blood
Pancreas
- Lies in the epigastric and left hypochondriac regions with its head in the C-shaped curvature of the duodenum
- Key exocrine function is to release digestive enzymes
Gallbladder
- Sac inferior and posterior to the right lobe of the liver
- Key function is to concentrate and store bile produced by the liver until it is needed for digestion
Answer the following questions about the liver:
List the lobes of the liver
Describe the vessels that carry blood into, through and out of the liver
- Right, left, caudate, quadrate
- Into the liver: hepatic portal vein (deoxygenated, nutrient rich) and hepatic artery proper (oxygenated, nutrient poor)
Through the liver: the portal triad (contains branches of the hepatic portal vein, hepatic artery proper, and bile duct)
Out of the liver: Hepatic veins drain blood into the inferior vena cava
Trace the path urine takes in the urinary system, listing the structure and the function of each major organ
How is back flow of urine from the urinary bladder prevented?
Kidneys - filter waster products from the bloodstream and convert the filtrate into urine
Ureters - transport urine from the kidney to bladder via peristalsis
Urinary bladder - storage of urine
Urethra - transports urine from bladder to the outside of the body
Entry of ureters into the urinary bladder are angled as to prevent back flow
Trace the route of inhaled air from the external nares to the alveolus, naming all of the structures through which the air passes
In the route, where does air enter the respiratory zone?
External nares, nasal cavity, internal nares, pharynx, larynx, trachea, primary bronchi, secondary bronchi, tertiary bronchi, bronchioles, terminal bronchioles, respiratory bronchioles, alveolar ducts, alveoli
Respiratory bronchioles
Compare and contrast the structure and function of the small intestine and the large intestine
Small intestine
- Site of most enzymatic digestion and absorption, longer
- Receives secretions provides by pancreas and gall bladder (liver)
- Lies in the centre of the abdominal cavity and forms 3 subdivisions
- Contains circular folds, villi and microvilli to increase SA for absorption
Large intestine
- Site for most water and electrolyte absorption, shorter
- Solidifies digested material into faeces
- Lies around the edges of the abdominal cavity and forms 4 colons
- Villi are absent, but contains goblet cells and intestinal crypts
List the 3 basic layers of the arterial and venous wall (1.5)
Which of these layers is responsible for changing vessel diameter (0.5)
Describe the differences in the gross anatomy of veins and arteries (3)
Tunica intima, tunica media, tunic externa
Tunica media
Arteries have a smaller lumen than veins. Arteries have a thinner tunica externa than veins. Arteries have more elastin and thicker walls than veins
List and describe the 5 steps involved in the cardiac conduction cycle of the heart
- SA node initiates an electrical impulse
- Signal travels to the AV node and is delayed for 0.1 seconds, allowing the atria to contract
- The signal travels along the AV bundle through o the right and left bundle branches
- From the bundle branches, the signal travels to the ventricles via the Purkinje fibres
- Purkinje fibres spread the signal to allow for rapid contraction of ventricles
Name the three major peripheral nerves that extend down the upper limb to the hand, describe their course through the upper limb, and name two skeletal muscles that each nerve innervates
Median nerve
- Passes down the middle anterior upper limb and through the carpal tunnel to the hand, branching along the way
- Pronator teres, Pronator quadratus
Ulnar nerve
- Passes down the medial side of the upper limb. However, at the elbow it briefly passes posterior to the medial epicondyle of the humerus
- Flexor carpi ulnaris, adductor pollicis
Radial nerve
- Passes down the posterior arm. However, at the elbow it briefly passes anterior to the lateral epicondyle of the humerus
- Extensor digitorum, Supinator
